Śatapatha Brāhmaṇa ("of a hundred paths") 7.1.2.9

7.1.2.9

sa yaḥ sa prajāpatirvyasraṃsata | ayameva sa yo 'yamagniścīyata tadyadeṣokhā riktā śete purā pravarjanādyathaiva tatprajāpatirutkrānte prāṇa utkrānte vīrye srute 'nne rikto 'śayadetadasya tadrūpam

And the Pragâpati who became relaxed is this same Agni who is now being built up. And when that fire-pan lies there empty before being heated, it is just like Pragâpati, as he lay there with the vital air and the vigour gone out of him, and the food having flowed out.